support enable dtmf tone (#976)

* support enable dtmf tone

* wip

* wip

lib/session/call-session.js

@@ -30,6 +30,7 @@ const {
 } = require('../config');
 const bent = require('bent');
 const BackgroundTaskManager = require('../utils/background-task-manager');
+const dbUtils = require('../utils/db-utils');
 const BADPRECONDITIONS = 'preconditions not met';
 const CALLER_CANCELLED_ERR_MSG = 'Response not sent due to unknown transaction';
 
@@ -1041,6 +1042,16 @@ class CallSession extends Emitter {
   async exec() {
     this.logger.info({tasks: listTaskNames(this.tasks)}, `CallSession:exec starting ${this.tasks.length} tasks`);
 
+    // calculate if inbandDTMF tone is used
+    const voip_carrier_sid = this.req.has('X-Voip-Carrier-Sid') ? this.req.get('X-Voip-Carrier-Sid') :
+      this.req.has('X-Requested-Carrier-Sid') ? this.req.get('X-Requested-Carrier-Sid') : null;
+
+    if (voip_carrier_sid) {
+      const {lookupVoipCarrierBySid} = dbUtils(this.logger, this.srf);
+      const [voipCarrier] = await lookupVoipCarrierBySid(voip_carrier_sid);
+      this.inbandDtmfEnabled = voipCarrier?.dtmf_type === 'tones';
+    }
+
     while (this.tasks.length && !this.callGone) {
       const taskNum = ++this.taskIdx;
       const stackNum = this.stackIdx;
@@ -2060,6 +2071,8 @@ Duration=${duration} `
         };
       }
 
+      this._enableInbandDtmfIfRequired(this.ep);
+
       // we are going from an early media connection to answer
       if (this.direction === CallDirection.Inbound) {
         // only do this for inbound call.
@@ -2620,6 +2633,7 @@ Duration=${duration} `
   }
 
   _configMsEndpoint() {
+    this._enableInbandDtmfIfRequired(this.ep);
     const opts = {
       ...(this.onHoldMusic && {holdMusic: `shout://${this.onHoldMusic.replace(/^https?:\/\//, '')}`}),
       ...(JAMBONES_USE_FREESWITCH_TIMER_FD && {timer_name: 'timerfd'})
@@ -2629,6 +2643,20 @@ Duration=${duration} `
     }
   }
 
+  async _enableInbandDtmfIfRequired(ep) {
+    if (ep.inbandDtmfEnabled) return;
+    // only enable inband dtmf detection if voip carrier dtmf_type === tones
+    if (this.inbandDtmfEnabled) {
+      // https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/Modules/mod-dptools/6587132/#0-about
+      try {
+        ep.execute('start_dtmf');
+        ep.inbandDtmfEnabled = true;
+      } catch (err) {
+        this.logger.info(err, 'CallSession:_enableInbandDtmf - error enable inband DTMF');
+      }
+    }
+  }
+
   /**
    * notifyTaskError - only used when websocket connection is used instead of webhooks
    */

lib/utils/db-utils.js

@@ -215,11 +215,23 @@ module.exports = (logger, srf) => {
     }
   };
 
+  const lookupVoipCarrierBySid = async(sid) => {
+    const pp = pool.promise();
+    try {
+      const [r] = await pp.query('SELECT * FROM voip_carriers WHERE voip_carrier_sid = ?', [sid]);
+      return r;
+
+    } catch (err) {
+      logger.error({err}, `lookupVoipCarrierBySid: Error ${sid}`);
+    }
+  };
+
   return {
     lookupAccountDetails,
     updateSpeechCredentialLastUsed,
     lookupCarrier,
     lookupCarrierByPhoneNumber,
-    lookupGoogleCustomVoice
+    lookupGoogleCustomVoice,
+    lookupVoipCarrierBySid
   };
 };